Vending machine



July 28, 1959 Q o. G. GISSER ET AL VENDING MACHINE 6 Sheets-Sheet 1 Filed July 23, 1954 //v VENTORS A T TORNE rs y 28, 1959 D. s. GISSER ET AL 2,896,763

VENDING MACHINE Filed y 1954 s Sheets-Sheet 2 /NVENTOR$ fivl/xb 6. G/Isser Z eonardPJei/er/ 47' TORNEYS y 28, 1959 D. G. GlssER ET AL 2,895,763

VENDING MACHINE Filed July 23, 1954 6 Sheets-Sheet 3 7 ATTORNEYS.

July 28, 1959 D. G. GISSER ET AL 2,896,763

. VENDING MACHINE I Filed July 25, 1954 v 6 Sheets-Sheet 4 r I" I llllllllllmmulm /N l/EN TOPS Dal/f0 6. G/sser [earrardFSwferg m/M ATTORNE Y5 D. 'e. GISSER AL 2,896,763

July 28, 1959 VENDIN MACHINE 6 Sheets-Sheet 5 Filed July 23, 1954 a r Y Z w 6 T Z A Z w 6 Sheets-Sheet 6 DEL/van 'MOTO/P /NVEN'TOR$ R5701? BUTTON VENDING MACHINE D. G. GISSER ET AL BELT MOTOR July 28, '1959 Filed July 25, 1954 in Q W0 pm 0%.

ATTORNEYS United States Patent VENDING MACHINE David G. Gisser, Loudonville, N.Y.,'and Leonard P. Seifert, Easton, Pa., assignors to Lehigh, Inc., Easton, 'Pa., a corporation of Pennsylvania Application July 23, 1954, Serial No. 445,322

17 Claims. (Cl. 194-4) Our invention relates to vending machines and particularly to a mechanism which is adapted to receive a piece of paper currency or bill, check the same to determine whether or not it is valid and, if valid, to place the machine in operative condition.

Coin operated machines for selling low priced merchandise, such as cigarettes, chewing gum and the like,

are well known but, so far as we are aware, there is not, at the present time, any machine which is adapted to be actuated by paper currency.

One of the distinguishing features of a dollar bill, for example, is, of course, the engraving thereon, and a close examination of a dollar bill will reveal that, between the second and third border lines, along both the top and bottom of the face thereof, are printed very fine vertical lines about long and spaced about 70 to the inch. If a fine line of light is focused on the bill parallel to these lines and moved across said lines, the light reflected from or transmitted through the paper will vary at a rate determined by the number of lines per inch on the bill and the relative speeds of the bill and the light. This varying light can be changed into a varying electric cur-' rent which can be amplified and utilized for placing a vending machine in operable condition providedv the frequency of the current corresponds to that which would be developed when a genuine dollar bill is tested in the machine.

One of the objects of our invention is to provide a bill accepting and testing mechanism which will place a vending machine in condition to be operated by the party placing a genuine bill in the machine so that the goods purchased will be delivered to him. Another object is to provide a device of this character which will place the machine in operating condition only when a genuine bill is inserted therein. Another object is to provide a bill tester in which the bill inserted in the machine, even if a genuine bill, may be returned to the customer, if he so desires, before the mechanism for delivering'the goods is actuated. Another object is to provide a bill tester which will positively reject any non-genuine bills or other pieces of paper or the like which have been inserted in the machine. I

More specifically, an object of our invention is to provide, in a vending machine, a beam of light which will have its focal zone in fixed, spaced relation to the source of said light, means for effecting relative movement of a dollar bill and said beam of light at a substantially uniform, predetermined rate with the above mentioned fine lines on said bill maintained in the focal zone of said light, and means which will'be controlled by the rate at which said beam is' intercepted by said lines for placing said machine in condition to be operated by a customer.

We accomplish these objects by the novel means described below and illustrated in the accompanying drawings in which Fig. 1 is a diagrammatic, perspective view, with portions broken away, of the essential elements of our device;-

Fig. 2 is a plan view of the device partially in section;

Patented July 28, 1959 Fig. 3 is a right hand side or end view of the device;

Fig. 4 is a left hand end view;

Fig. 5 is a vertical section of the device about in the broken plane 55 of Fig. 2; and

Fig. 6 is a wiring diagram.

Referring first to Fig. 1, 1 represents the slot through which a dollar bill is inserted by the customer. 2 is a comparatively large pulley which is driven by a synchronous motor 3 having a pulley 4 on the shaft thereof which, in turn, drives the belt 5, in the direction shown by the arrows, around the idler 6, the pulley 2 and the idler 7. 8 is a normally open microswitch having a depending, actuating element 9 which is moved by the bill 10 as it is inserted, to close the switch 8 which energizes the motor 3. The bill is gripped between the belt 5 and the pulley 2 with a long marginal edge, bearing the fine lines 11, projecting beyond the side of the pulley. As soon as the end of the bill is pulled past the actuating element 9 of switch 8, this switch opens and the motor 3 would stop unless some other means is provided to maintain it energized. Hence, another microswitch 12 having a depending element 13 which cooperates with the bill maintains the electrical circuit through the motor 3 as will be apparent from the wiring diagram shown in Fig. 6.

14 is an exctiter lamp and 15 is a lens which focusesv will be cut off, or at least substantially reduced, whenever the beam is intercepted by one of the lines 11 on the bill 10.

In order to energize the exciter lamp, a normally open microswitch 18 is provided having a depending, actuating element 19 which is moved by the bill 10 to close said switch and maintain it closed, and the exciter lamp lighted until the trailing end of the bill passes beyond element 19.

i For reasons which will be later explained, it is desirable that the movement of the bill through the machine be stopped before it passes out of the engagement of pulley 2 and belt 5. Thus, when the trailing end of the bill passes out of cooperation with the elements. which actuate switches 12 and 18 at the same time these switches automatically open and the motor 3 and the lamp 14'are tie-energized.

In the event that the bill, for any reason whatever, fails to place the machine in condition to effect a delivery of goods therefrom, or the customer desires to recover the bill, there is provided, somewhere on the machine, a bill-return, button-operated switch 20 (see Fig. 6). The normal position of this switch is as shown in Fig. 6, but it will be clear that, when the button is pressed, a direct circuit will be established between the motor 3 and the source of power 21 which will start the motor and carry the bill downwardly towards the chute 22, shown in Fig. 1, which has a lip 23 running in contact with the belt 5 so that the advancing end of the bill will pass over said lip and out the chute 22.

From the foregoing, it will be apparent that the validity of the bill is being tested by the presence or absence of the short lines ruled thereon and which have a fixed be changed into a varying electric current by any photoelectric device and this current can be amplified and e 2,896,763 e m f used to control the operative condition of the machine insofar as the delivery of goods therefrom is concerned. In other words, the amplifier and the control means should respond only to currents of one particular frequency. i

Since the light transmitted through the bill is used to excite the phototube, or other photoelectric device, a dollar bill may be inserted in the machine, face up or face down, since the fine lines 11 are adjacent each of the long edges. of the bill.

In order to utilize the principle described above for checking the validity of a bill, equipment of three general types is required. First there must be a mechanical arrangement for moving a dollar bill at a constant speed, or for effecting relative movement between the bill and a scanning means at a constant speed. The second type of equipment is optical, for use in the scanning aspect of the apparatus. The third general type of equipment is composed of the electronic components for actuating the apparatus. To utilize the checking equipment for .effecting delivery of the goods being vended, there must be mechanism for correlating the bill acceptance and goods delivery operations.

Referring now more particularly to Fig. 6, it will be apparent that power from the source 21 is continuously applied to the primary of the transformer represented.

generally by the numeral 24. The transformer is provided with secondary windings 25 and 26. The secondary winding 25 is designed to supply power for lighting the filaments 27, 28, 29, 3h, 31 and 32 of the tubes 33, 34, 35, 36, 37 and 38, respectively, and also for lighting the filament of the exciter lamp 14 when the bill actuated switch 18 is closed.

The electronic unit is required to analyze a light of varying intensity and to report the presence of variations of a particular frequency. The unit which will be described in detail below is sensitive to the average intensity of the light, its amplitude of variation, and the rate of variation. The current through the phototube 17, which also flows through the grid of tube 33, varies essentially with the light intensity on its cathode and, for the small quantity of light passing through a valid dollar bill, the phototube and grid current is small, the

grid is reasonably negative, and the input impedance; of

the tube is quite high. A small variation in the light intensity then causes a small variation in current resulting in a relatively large change in grid potential. If the light striking the phototube has passed through material which is less opaque than that of a valid dollar bill, there results a larger phototube and grid current, a somewhat less negative grid, and a smaller input impedance across which small variations in current can produce little alternating grid voltage. Thus, the sensitivity to small variations in light intensity is a function of the average light on the phototube cathode.

The alternating voltage produced at the control grid of tube 33 by the variation in the intensity of the illumination of phototube 17 is amplified by tube 33' and coupled through blocking condenser 39 to the tuned (Jill-- cuit including condenser 40 and coil 41 which is adjusted to resonate at the frequency determined by the speed of a genuine bill through the light beam and the spacing of the fine lines 11 thereon.

The tubes 34 and 35 are used in conventional amplifier circuits but the output voltage at the plate of tube- 35 is fed back through blocking condenser 42 and resistor 43 to the cathode of tube 34 producing degencra tion at all frequencies. Feedback is also provided through resistor 44 to the grid of tube 34 producing regeneration at frequencies near the resonant frequency of the tuned circuit 4! and 41. The overall efiTect is additional rejection of voltages whose frequencies are far removed.

4 I tion with the rectifier 45, filter condensers 46 and 47, and adjustable resistor 48 supplies a positive direct voltage for tubes 17, 33, 34, 35 and 38, and a negative (with respect to ground) voltage which is applied to the second grid of thyratron 38 through resistors 49 and 50 and which is sufiiciently large to prevent the thyratron from conducting current. The alternating voltage at the plate of tube 35 in combination with the rectifier 36 and condenser 51 produces a direct voltage across resistor 49 of proper polarity to raise the voltage of the second grid of thyratron 38 in the positive direction. The potential of the second grid of the thyratron 38 does not rise immediately however, since a definite time interval is required to charge condenser 52 through resistor 50. If a genuine bill has been scanned, the alternating voltage output of tube 35 will be of suflicient magnitude and maintained for such an interval of time that the potential of the second grid of the thyratron exceeds the critical value required for firing or conduction.

The first grid of the thyratron 38 is normally at zeropotential but is driven negative when the voltage at the grid of tube 35 is rectified by the tube 37. The normal voltage produced by scanning a valid bill causes the potential of the first grid of the thyratron to become negative by a very small amount with negligible effect on the operation of the thyratron. However, if the specimen scanned has closely spaced lines imprinted thereon which are longer, blacker, or in some way much more distinct than those on a valid bill, the larger variations of light produce a large voltage at the grid of tube 35 causing the first grid of the thyratron to become sufiiciently negative to prevent firing even if the second grid becomes quitepositive. Condenser 53 acts as a filter for rectifier tube 37 and, in conjunction with resistor 54 maintains the large negative voltage at the first grid of the thyrathron until the sample has. been scanned and the voltage at the second grid of the thyratron has been returned to its normal negative value by the recharging of condenser 52. The thyratron will fire only when there are lines on the specimen scanned which are properly spaced, the average density of the paper is roughly correct, and the. distinctiveness of the lines on the sample is of the same order of magnitude as those on a valid bill.

The click will indicate to the customer that his bill has.

been accepted and that the machine is ready to deliver his selected goods. A light, bell or other signal could be operated by the relay coil 55 to indicate bill acceptance.

After the thyratron fires and the machine is ready to deliver goods, if the purchaser desires to have his bill returned to him instead of purchasing goods, he merely presses the button 58 on switch 20, which is normally in the position shown in Fig. 6. This breaks the circuit through the relay coil 55 which is closed when the thyratron fires, and closes the other circuit through switch- 20 which energizes the motor 3, causing the drum 2 to rotate and eject the bill through the chute 22.

Referring now more particularly to Fig. 5, the goods 59 to be delivered by the machine are stored in a plurality of vertical columns 60 in substantially the same manner that packages of cigarettes are stored in the present coin-operated vending machines. In front of each column, the casing is provided with a transparent windowfil and a specimen 62 of the goods in each column is set up in the casing behind the windows.

Having selected the goods which he Wishesto buy, thepurchaser pushes the button 63 in front of the column containing said goods, As the button moves in, the

Once the: thyraton has fired, it continues to conduct current as long as a positive voltage is applied to its plate even if the" 3 projection 64 thereon contacts the plate 65 which depends from the slide 66 and which is normally held in the position shown in Figs. 2. and by the springs 67. Each slide has secured thereto a goods pusher 68 which is moved through the opening 69 in the bottom of each column by the means about to be described.

Rotatably mounted in roller bearings 70 is an elongated, hollow, fiber cylinder 71 having longitudinally spaced slots 72 therein which are normally positioned to receive the lower ends of the depending plates 65 when the buttons are pushed. The cylinder 71 is normally held with the slots in this position by means of the projection 73 on the end of the cylinder, the stop 74, and the spring 74' (see Fig. 1). When any of the buttons 63 is pressed and the depending plate 65 is moved inwardly thereby, the plate enters the slot 72 in the cylinder 71, and the cylinder is turned slightly in a counterclockwise direction.

Referring now more particularly to Figs. 1, 4 and 6, there is a rod 75 projecting from the end of the cylinder 71 .which is in contact with an element 76 of a normally open switch 77. Switch 77 is connected in series with contacts 100 on relay 55 which are closed only when this. relay is actuated by current through thyratron 38 (Fig. 6). .If contacts 100 are closed by acceptance of a bill, then when rod 75 moves away from element 76 and closes switch 77, a circuit is completed which may be traced from one side of the supply line, through switch 77, through contacts 100, to the delivery motor 78, and then to the other side ofthe supply line. This circuit actuates motor 78 and turns crank arm 79 in a clockwise direction (as viewed in Figs. 1 and 4). The motor 78 is provided with appropriate gearing (not shown) so that the crank arm 79 connected thereto turns at a comparatively low rate of speed. Connected to the crank arm 79 is a link 80 which slidably cooperates through the slot 81 with the end of the rod 75. At the upper end of the crank arm 79, is a cam 82 which cooperates with a roller 83 on an arm 84 and actuates the switch 57, normally in the position shown in Fig. 6, to break the circuit from the thyratron through the relay coil 55 and establish a new circuit which may be traced from one side of the power line and through the motor 78 which continues to turn in the direction of the arrow shown in Fig. l. The motor initially turns the cylinder 71 counterclockwise and the plate 65 in slot 72 moves the pusher 68 into the column to pushthe lowermost package in the column out through the opening 85 in the back of the column (see Fig. 5) and against the depending plate 86 which is pivotally mounted at 87. A normally open switch 88 (see Figs. 1 and 6) has a depending element 89 cooperating with the projecting bar '90 at the bottom of the plate 86 and which normally holds the switch 88 open. However, as the plate 86 is swung by the package pushed into contact therewith, the switch 88 closes and energizes the coil 91 of .the solenoid actuating the arma ture 94 and closing switches 92 and 93. When the armature 94 (see Figs. 1 and3) of the solenoid is moved by the energization of the coil 91, the connecting rod 95 is drawn .to the .left as viewed in Fig. 1 (to the right as viewed in Fig. 3) and swings the lip 23 upwardly and away from the .belt 5 so that a valid bill placed in the machine will, as the drum rotates, deliver the bill into an appropriate receptacle in the machine rather than pass it out the chute .22.. When the package is pushed all ,the way out of the column, it drops downwardly into the space 96 in the machine (see Fig. 5) from which it slides out to the purchaser through the delivery trough 97. r, Referring now. more particularly to Fig. 1, the driving means which connects the motor 78 and the cylinder 71 will effect an oscillating movement of said cylinder for each turn of the crank 79. Initially, and during the delivery of the goods, the cylinder 71 rotates counterclockwise, as viewed in Fig. 1, until the projection 73 on the end of the cylinder contacts the stop 98, at which time the link 80 has moved about to dead center and is thereafter retracted to rotate the cylinder 71 in a clockwise direction back to its initial position, thus open ing the switch 77 by its contact with the element 76 and restoring the switch 77 to its initial position, as shown in Fig. 6. When the plate 86, which has been swung by the goods moving out of the column so that the switch 88 is closed which energizes the solenoid coil 91, swings back to its normal position when the goods drop into the space 96, the switch 88 is automatically opened and the switches 92 and 93 and the lip 23 are restored to their normal, initial positions.

To summarize the operation, the following is a list of events as they occur in sequence.

(1) A bill is inserted into entrance slot 1 and switch 8 is closed, starting belt motor 3.

(2) The bill is scanned by photoelectric means and, if genuine, relay 55 is actuated, closing contacts 100 and opening contacts 56 to stop the belt motor after the bill moves beyond switches 8 and 12;

(3) Button 63 is pushed in, cylinder 71 is rotated slightly and switch 77 is closed, starting the delivery motor 78 (through closed contacts 100).

(4) Cylinder 71 engages the pusher assembly (by means of plate 65) and pushesthe lowest article 59 through space 85.

(5) Shortly after cylinder 71 starts to move, switch 57 is actuated by cam 82 connecting the delivery motor 78 by another circuit and, at the same time, the anode circuit of thyratron 38 is broken and relay 55 is normalized, opening contacts 100.

' (6) The article falls and actuates plate 86, closing switch 88, actuating relay 91, and closing contacts 92 and 93. Contacts 93 are locking contacts which insure the continued actuation of the relay after switch 88 is opened. Contacts 92 complete a circuit which starts the belt motor and delivers the bill to a compartment.

(7) Motor 78 continues to turn and crank arm 80 reverses the motor of cylinder 71, returning it to its original position.

(8) When cylinder 71 is returned, contacts 77 are opened and contacts 57 are normalized, opening the circuit to the delivery motor 78 and cutting 011? the supply.

to coil 91, thereby normalizing the solenoid. Also, the belt motor is disconnected.

-' (9) At this time the relays and switches are in their 9 closed.

the true scope and spirit of our invention in its broader aspects.

What we claim is:

I. In a vending machine, the combination with an exciter lamp; of means for focusing a narrow beam of light from said lamp in a zone in fixed spaced relation thereto; means for moving a bill having a multiplicity of closely and uniformly spaced parallel lines thereon, when inserted in said machine, at a substantially fixed rate with said lines moving through the focal zone of said beam to be scanned thereby; means positioned to be illuminated by said beam during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as aflected bysaid lines, switches 7 actuatable by said bill when inserted in said machine for energizing said lampand said bill-moving means; a billactuated switch for stopping said bill-moving means when the bill has moved to a predetermined position; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; and

means responsive to said current when varying at a predetermined rate for rendering said delivery meansoperable.

2. In a vending machine, the combination with an exciter lamp; of means for focusing a narrow beam of light from said lamp in a zone in fixed spaced relation thereto; means for. moving a bill having a multiplicity of closely and uniformly spaced parallel lines thereon, when inser ted in said machine, at a substantially fixed rate with said lines moving through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as affected by said lines; switches actuatable by said bill when inserted in said machine for energizing said lamp and said bill-moving means; a bill actuatable switch for stopping said billmoving means as the trailing edge of said bill reaches a predetermined position; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; means responsive to said current when varying at a predetermined rate for rendering said delivery means operable; and means actuated by said delivery means when operated for starting said bill-moving means to deposit said bill in said machine.

3. In a vending machine, the combination with an exciter lamp; of means for focusing a narrow beam of light from said lamp in a zone in fixed spaced relation thereto; means for moving a bill having a multiplicity of closely and uniformly spaced parallel lines thereon, when inserted in said machine, at a substantially fixed rate with said lines moving through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as alfected by said lines; switches actuatable by said bill when inserted in said machine for energizing said lamp and said billmoving means; a bill-actuated switch for stopping said bill-moving means when the bill has moved to a predetermined position; means for effecting a delivery of goods fromv said machine; means normally maintaining said delivery means inoperable; means responsive' to said current when varying at a predetermined rate for rendering said delivery means operable; and manually controlled means, operable when said delivery means is inoperable,

for starting said bill-moving means and effecting an ejec-' tion from said machine of the bill moved thereby.

4. In a vending machine, the combination with an exciter lamp; of means for focusing a narrow beam of light from said lampin a zone in fixed spaced relation thereto; means. for moving a bill having a multiplicity of closely and uniformly spaced parallel lines thereon, when inserted in said machine, at a substantially fixed rate with said lines moving through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as affected by said lines; means for amplifying said current; switches actuatable by said bill when inserted in said machine for energizing saidlamp and. said bill-moving means; a bill actuated switch for stopping said bill-moving means as the trailing edge of the bill reaches a predetermined position; means for effecting a delivery of goods from said machine; means normally maintaining said deliverymeans inoperable; and means responsive to said amplified current when varying at a'p redetermined, rate for rendering said delivery means operable.

5. In a vending machine, the combination with an ex-.- citer lamp; of means for focusing a narrow beam of light from said lamp in a zone in fixed spaced. relation thereto; means for moving a bill having a multiplicityof closely. and uniformly spaced parallel lines thereon, when in-l serted in said machine, at a substantially fixed rate with said lines moving through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam during the scanning of said lines for producing an electric current proportional to. the intensity of the illumination thereof as afliected by said lines;'switches actuatable by said bill when inserted in said machine for energizing said lamp and said billmoving means; a bill actuated switch for stopping said bill-moving means when the bill has reached a predetermined position; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; means responsive to said cur'-. rent when varying at a predetermined rate for rendering said delivery means operable; and manually controlled 7 means operable after the first stoppage of said bill-moving means, for starting said bill-moving means and efifecting a delivery of said bill from said machine.

6. In a vending machine, the combination with a source of light, of means for focusing a narrow beam of light from said source in a zone in fixed spaced relation to said source; means for effecting relative movement, at a sub-. stantially fixed rate, of said light beam and a bill inserted in said machine having a multiplicity of closely and uniforml'y spaced parallel lines thereon while maintaining the path of said lines through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam of light during the scanning of said lines for producing an electric current proportional. to the intensity of the illumination thereof as alfected by said lines; means for stopping the relative movement of said bill and shutting off said light beam when said movement has proceeded to a predetermined extent; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; means responsive to said current when varying at apre determined rate for rendering said delivery means operable; and means actuated by said delivery means,- when operated, which moves the bill to a compartment in the machine.

7. In a vending machine, the combination with a source of light, of means for focusing a narrow beam of light from said source in a zone in fixed spaced. relation to said source; means for effecting relative movement, at a substantially fixed rate, of said light beam and a bill inserted in said machine having a multiplicity of closely and uniformly spaced parallel lines thereon, while maintaining the path of said lines through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam of light during the scanning of said lines for producing an electriecurrent proportional to the intensity of the illumination thereof as affected by said lines; means for stopping the relative movement of said bill and shutting off said light beam when said movement has proceeded to a predetermined extent; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; means responsive to said current when varying. at a predetermined rate for rendering said delivery means operable; and manually controlled means operable after the stoppage of saidrelati've movement and before said delivery means is put in operationwhich moves the bill to 'eifect an ejection of s'aid'bill from. said machine. 7

8. In a vending machine, the combination with-a source, oflight, of .meansfor focusing a narrow beam of light. from said source in a zone in fixed spaced relation to said source; means for effecting relative movement, at asubstantially fixed. rate, of said light beam and a bill inserted in said machine having a multiplicity ofclosely and uni- 9 formly spaced parallel lines thereon, while maintaining the path of said lines through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam of light during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as affected by said lines; means for amplifying said current; means for stopping the relative movement of said bill and said light beam when said movement has proceeded to a predetermined extent; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means inoperable; means responsive to said amplified current when varying at a predetermined rate for rendering said delivery means operable; and means actuated by said delivery means, when operated, which moves the bill to effect its deposit in said machine.

9. The structure set forth in claim 8 in which said amplifying means includes a filter adapted to pass only a current of the predetermined frequency.

10. In a vending machine, the combination with a source of light, of means for focusing a narrow beam of light from said source in a zone in fixed spaced relation to said source; means for effecting relative movement, at a substantially fixed rate, of said light beam and a bill inserted in said machine having a multiplicity of closely and uniformly spaced parallel lines thereon, while maintaining the path of said lines through the focal zone of said beam to be scanned thereby; photoelectric means positioned to be illuminated by said beam of light during the scanning of said lines for producing an electric current proportional to the intensity of the illumination thereof as affected by said lines; means for amplifying said current; means for stopping the relative movement of said bill and said light beam when said movement has proceeded to a predetermined extent; means for effecting a delivery of goods from saidrmachine; means normally maintaining said delivery means inoperable; means responsive to said amplified current when varying at a predetermined rate for rendering said delivery means operable; and manually controlled means operable after the stoppage of said relative movement and before said delivery means is put in operation which moves the bill to effect an ejection of said bill from said machine.

11. The structure set forth in claim 10 in which said amplifying means includes a filter adapted to pass only a current of the predetermined frequency.

12. In a bill operated vending machine of the type in which a marginal portion of a bill having a multiplicity of closely and uniformly spaced parallel lines thereon is scanned by a beam of light for determining the validity of the bill; the combination with a rotatable cylindrical drum; of a mounting therefor; a belt extending a substantial distance around said drum for driving the same; a synchronous motor for driving said belt at a predetermined, substantially uniform speed; means forming a passage through which a bill may be introduced into said machine between said drum and said belt and carried thereby with said marginal portion of said bill projecting laterally beyond said belt and drum; a source of light; means focusing a narrow beam of light from said source in a zone through which said lines will pass; photoelectric means positioned to intercept said beam of light after it is interrupted at a predetermined frequency by said lines for producing an electric current varying at said frequency; means for amplifying said current; means for effecting a delivery of goods from said machine; means normally maintaining said delivery means vinoperable; and means responsive to said amplified current when varying at said predetermined frequency for rendering said delivery means operable.

13. The structure set forth in claim 12 in which the amplifying means includes a filter adapted to pass only a current of said predetermined frequency.

14. The structure set forth in claim 12 including a switch actuated by said bill as it is inserted in said passage for energizing said motor.

15. The structure set forth in claim 12 including a first switch actuated by said bill as it is inserted in said passage for energizing said motor; and a second switch actuated by said bill after a portion thereof has moved adjacent to the focal zone of said light beam for energizing said light source.

16. The structure set forth in claim 12 including a first switch actuated by said bill as it is inserted in said passage for energizing said motor; a second switch actuated by said bill for energizing said light source; and a third switch actuated by said bill for stopping said motor while said bill is still between said belt and drum.

17. The structure set forth in claim 12 including a first switch actuated by said bill as it is inserted in said passage for energizing said motor; a second switch actuated by said bill after a portion thereof has moved adjacent to the focal zone of said light beam for energizing said light source; a third switch actuated by said bill for stopping said motor while said bill is still between said belt and drum; and manually controlled means for starting said motor after the stopping thereof and efiecting an ejection of said bill from said machine.

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